While investigating ways to improve X10 reliability (eventually hitting upon the X10RfConfiguration), I considered different approaches to see if any of the (often time-consuming and expensive) changes I was making in my X10 configuration were helping at all.

Total harmonic distortion (THD) measurements are one of the most commonly quoted in audio. Contrary to belief in some circles, these can be very useful if performed properly, and reveal much about the overall performance of an amplifier.

This 3 channel 15 LED spectrum analyzer is the perfect addition to any audio amp project. It produces fantastic displays on three LED bars that can be individually adjusted for any particular frequency range. The circuit will take line level output from most any audio source, and operates on 12V DC. This means that it can even be run in a car.

A spectrum analyzer can be a powerful tool for keeping your studio well tuned. Besides its obvious uses - for adjusting octave or one-third octave room equalizers - a spectrum analyzer can also be used to check the response of a tape recorder, or even help identify the rumble frequencies in an air conditioner.